1HH1

THE STRUCTURE OF HJC, A HOLLIDAY JUNCTION RESOLVING ENZYME FROM SULFOLOBUS SOLFATARICUS

Summary for 1HH1

• Entry DOI: 10.2210/pdb1hh1/pdb
• Descriptor: HOLLIDAY JUNCTION RESOLVING ENZYME HJC (2 entities in total)
• Functional Keywords: holliday junction resolvase, homologous recombination, nuclease domain, archaea
• Biological source: SULFOLOBUS SOLFATARICUS
• Total number of polymer chains: 1
• Total formula weight: 16039.79

Authors

Bond, C.S.,Kvaratskhelia, M.,Richard, D.,White, M.F.,Hunter, W.N. (deposition date: 2000-12-18, release date: 2001-04-06, Last modification date: 2024-05-08)

Primary citation

Bond, C.S.,Kvaratskhelia, M.,Richard, D.,White, M.F.,Hunter, W.N.
Structure of Hjc, a Holliday Junction Resolvase, from Sulfolobus Solfataricus
Proc.Natl.Acad.Sci.USA, 98:5509-, 2001

PubMed Abstract: The 2.15-A structure of Hjc, a Holliday junction-resolving enzyme from the archaeon Sulfolobus solfataricus, reveals extensive structural homology with a superfamily of nucleases that includes type II restriction enzymes. Hjc is a dimer with a large DNA-binding surface consisting of numerous basic residues surrounding the metal-binding residues of the active sites. Residues critical for catalysis, identified on the basis of sequence comparisons and site-directed mutagenesis studies, are clustered to produce two active sites in the dimer, about 29 A apart, consistent with the requirement for the introduction of paired nicks in opposing strands of the four-way DNA junction substrate. Hjc displays similarity to the restriction endonucleases in the way its specific DNA-cutting pattern is determined but uses a different arrangement of nuclease subunits. Further structural similarity to a broad group of metal/phosphate-binding proteins, including conservation of active-site location, is observed. A high degree of conservation of surface electrostatic character is observed between Hjc and T4-phage endonuclease VII despite a complete lack of structural homology. A model of the Hjc-Holliday junction complex is proposed, based on the available functional and structural data.

PubMed: 11331763
DOI: 10.1073/PNAS.091613398

Experimental method

X-RAY DIFFRACTION (2.15 Å)